BYLINE: Anna Ettlin

What do we need to achieve the energy transition? The technologies for producing and storing renewable energies are available and are constantly improving. The challenge lies in implementation. How do we bring business, politics, and the public, with their sometimes conflicting interests, under one (solar) roof? Empa researchers Harald Desing, Hauke Schlesier, and Marcel Gauch from the Technology and Society laboratory have developed a proposal on how the energy transition could be implemented quickly, sustainably, and in a socially acceptable manner – whether worldwide, in Switzerland, or just in a single municipality. The study was published in the journal Progress in Energy.

The researchers call their model the “solar basic service“. At its core is the idea that every person should receive a personal solar power budget of 500 watts (equivalent to 4,400 kilowatt hours per year) – financed by the general public. “Many essential services are already provided as basic services, such as roads, education, water supply, and sewage systems. So why not also the foundation for the energy transition?“, asks Harald Desing, the study’s lead author. “Foundation” is an important keyword. The solar basic service does not mean that the government should cover all of society’s energy needs free of charge. The 500 watts are sufficient – at least in Switzerland – to close the electricity gap created by the elimination of fossil fuels. However, the model proposed by the Empa researchers does not provide for public energy storage. This means that public solar power is only freely available when the sun is shining.

This restriction fulfills two important functions: On the one hand, it is intended to motivate individuals and companies to adjust their behavior and consume electricity primarily when it is available free of charge. The researchers refer to this as a “sunflower society,” which, like its namesake, always turns toward the sun. On the other hand, the omission of storage saves (public) money. “The construction of storage facilities increases the price tag for the energy transition,” says Desing. “That’s why, in our model, energy storage is not part of the basic service but rather a convenience that will require further private investments.”

Feasible within five years

Since 500 watts is slightly more than is needed to cover basic energy requirements, citizens can sell their unused energy. One possible scenario would be to use the energy equivalents as a means of payment for electric mobility or public transport. People who consume little energy would thus benefit most – an important social balancing factor, according to the researchers. “Today, the state uses subsidies to incentivize the energy transition,” says Desing. “But only the wealthy part of our society benefits from this, because you must be a landowner and provide the remaining capital. In our model, tenants and people without large savings also benefit from the joint investment.”

The researchers have calculated what it would mean in concrete terms to make solar basic service a reality in Switzerland. 500 watts of solar power correspond to approximately 21 square meters of solar surface area per person. “That would amount to about every third roof in Switzerland,” says Desing. Parking lots, noise barriers, and unused areas along motorways and railway lines could also be considered for this purpose. Desing emphasizes that it is important to mostly use already developed areas for the installation of solar panels and not to convert new land for this purpose. This is another reason why the basic service is based on solar energy: Photovoltaics can be installed quickly, easily, and in a decentralized manner; they blend in well with the cityscape, require little maintenance, and cause neither noise nor visual impairment.

In order to build a “public solar power plant” in Switzerland within five years, an investment of around 58 billion Swiss francs would be necessary. This corresponds to approximately 1% of Switzerland’s gross domestic product over five years – comparable to annual investments in roads (source) or double the military expenditure (source). The investment would pay for itself within six to seven years of commissioning – even though the public solar power plant is not designed to make a profit. “End consumers currently spend around 20 billion Swiss francs per year on fossil fuels in total. The basic solar service provides enough electricity to reduce this expenditure to zero.” The researchers estimate that the cost of regularly renewing the public solar power plant would amount to around 6,600 Swiss francs per person every 30 years.

Securing materials and a skilled workforce

Even if it is entirely feasible, installing a solar power plant of this size would not come without challenges. One is finding skilled workers. The researchers are calling for the plant to be built as quickly as possible so that the benefits of abandoning fossil fuels can be reaped sooner. Around 50,000 workers would be needed to convert Switzerland to basic solar power within five years. However, only a fraction of these workers would need an extensive training. The majority of the installation work can be carried out competently after just a few weeks of training. “There are already so-called solar camps where you can learn how to install solar panels in a very short time,” says Desing. The researcher also envisions a “solar year” in which young people work for the common good, for example as an alternative to military or civil service. Another advantage is that while Swiss funds flow abroad for fossil fuels, a large part of the investment in solar systems – namely the installation costs – would remain in Switzerland.

The materials needed for the panels pose another challenge – but researchers are convinced that this too can be solved. The main component of the cells, silicon, is the most common element in the Earth’s crust and is found everywhere in the world. More critical are silver, tin, and aluminum, which are used as conductors, solder, and frame and mounting materials, respectively. The demand for tin and aluminum can be greatly reduced by improving the design of the panels. Research is currently being conducted into substitute materials for silver – but this would not even be necessary for the construction of the public solar plant: “There is more silver in cutlery drawers worldwide than would be needed to provide 500 watts of solar power for everyone on Earth,” says Desing. The production of solar panels, which currently takes place mainly in China, could be relocated to Europe as part of the transition, thereby strengthening local industry.

Reversing climate change

The model described in the study is an initial proposal and flexible in many respects, says Harald Desing. Its exact implementation must be clarified in public discourse. The great advantage of the solar basic service is that any municipality, canton, or country implementing it would benefit immediately and directly. However, for the model to have the intended effect, a number of points must be given special consideration. “Free energy should not tempt people to waste it,” warns Desing. “Moreover, the development of the solar basic service must go hand in hand with the phasing-out of fossil fuels.” Special attention must also be paid to social fairness.

The researcher is convinced that solar basic service would make investments in other renewable energies such as wind and water more attractive, as they complement solar energy and are also available when solar power is scarce. Further expansion of solar capacity would also be worthwhile in certain cases. “The more solar capacity we have, the more electricity we can harvest at off-peak times or in bad weather, when solar panels deliver lower yield,” explains Desing. And when the sun shines again? “The surplus electricity could be used to remove historic CO₂ emissions from the atmosphere and process them into carbon-binding materials.” This is also currently a topic of research at Empa as part of the Mining the Atmosphere initiative.